head-tail-stream

Stream to only output the first or last lines of a stream, similarly as the head and tail CLI commands.

Installation

1npm install head-tail-stream

Usage

1var head = require('head-tail-stream');
2
3data.pipe(head(3)).pipe(process.stdout);
4/*
5line 1 of 20
6line 2 of 20
7line 3 of 20
8*/
9
10data.pipe(head(-2)).pipe(process.stdout);
11/*
12line 19 of 20
13line 20 of 20
14*/
15
16// both a head and a tail. same as `head(3, 2)`
17data.pipe(head({ head: 3, tail: 2 })).pipe(process.stdout);
18/*
19line 1 of 20
20line 2 of 20
21line 3 of 20
22...
23line 19 of 20
24line 20 of 20
25*/
26
27// head and tail with a custom message in between
28var headStream = head({
29    head: 3,
30    tail: 2,
31    // a string, array (for several lines) or null (no message)
32    message: [
33        '## long output was hidden',
34        '## run with different options to see a detailed output'
35    ]
36});
37data.pipe(headStream).pipe(process.stdout);
38/*
39line 1 of 20
40line 2 of 20
41line 3 of 20
42## long output was hidden
43## run with different options to see a detailed output
44line 19 of 20
45line 20 of 20
46*/

License

MIT license - http://www.opensource.org/licenses/mit-license.php